A recent development in farming has been the increased use of relatively large rolled bales of forage crops such as hay. The bales are typically five to eight feet in diameter and weigh approximately 1,000 to 3,000 pounds.
Material handling fork lift vehicles are well known, and there are numerous patents disclosing devices designed for manipulating and transporting the large round bales of forage crops. For example, U.S. Pat. No. 3,934,726 (to Martin) discloses a bale carrier for connection to the three point hitch of a tractor. The Martin carrier includes a pair of concentric pipes, an inner second pipe rotatably mounted in an outer first pipe, and a support frame. A tine is secured to each end of the second pipe for piercing engagement with a hay bale. The frame extends upwardly from the first pipe and a hydraulic cylinder is mounted on the frame to operate a single hook arm for engaging the upper portion of a bale.
Unlike the present invention, the hydraulic cylinder associated with the Martin carrier operates only the single, short upper arm; the lower tines must be moved into their bale-piercing position by hand. Additionally, the Martin carrier requires a bale to be pierced by the tines and, thus, there is no way simply to dump a bale into a carriage or transport vehicle. Rather, the Martin device requires that the bottom of a bale be brought into contact with a trailer surface or the ground to create enough friction to slide it off the tines. This piercing and removal process is hard on all the equipment involved.
Another bale retrieving and transporting apparatus is disclosed in U.S. Pat. No. 3,985,246 (Seymour). The Seymour retrieving and transporting apparatus includes a lower supporting structure consisting of tines adapted to be inserted under bale, a rear supporting structure, basically a frame, and a bale discharging means comprising a hydraulically operated arm for pushing a bale from the tines. The tines are fixedly mounted on the frame, and the Seymour apparatus does not include any means for contacting the upper portion of a bale to securely hold it while it is being transported.
Other rolled bale transportion devices are disclosed in U.S. Pat. Nos. 3,974,926 (Kopaska) and 4,459,075 (Eichenberger). The transporter disclosed by Kopaska, like that disclosed by Martin, relies upon frictional contact with the ground to remove a bale. The Eichenberger loading device is a trailer to which is attached a long, articulated, hydraulically operated pivoting arm for gripping and lifting the bales onto the trailer.
U.S. Pat. Nos. 4,092,050 (Sobeck), 4,580,843 (Lund) and 5,123,800 (Druse, Sr.) disclose bale carriers or rack assemblies, basically modified trailers, for transporting rolled bales. None of the latter three patents discloses means for picking up bales and loading them onto the carriers, nor is there any suggestion that such carriers or rack assemblies can be connected directly to bale lifters.
Despite the advancements and improvements in the art concerning the lifting and moving of relatively large rolled bales of material or other items, there still are some significant problems. For example, solid items can not be pierced, and if a bale is pierced as suggested in the Martin patent, there is no way simply to dump the bale from the lifter. Another problem is that the bales or material to be lifted may vary in size and, even in those patented devices with an arm or clamp for contacting the upper portion of a bale, e.g., the Martin or Kopaska devices, respectively, the arm or clamp is very short and has only a limited range of motion.
While the patent to Martin suggests that lower tines may be foldable to a storage position, the tines must be moved by hand. The Martin patent suggests that the Martin carrier does not interfere with the normal towing use of the tractor when the lower tines and the upper arm are positioned in nonworking positions, but there is no suggestion about how to couple a carriage of the general type disclosed in the Sobeck, Lund or Druse, Sr. patents to a bale manipulator so that two devices can be used in combination conveniently and safely.